Machine tool



May 17, 1938.

w. w. R01-TER ET Al.

Mimi-HNEA TooL Original Filed June 4, 1931 11 Sheets-Sheet l` W. w. POTTER ET AL.

MACHINE Tool,

May 17, 193s.

original Filed June 4, 1951 11 sheets-smeet 2 www A TTORNE'Y 'a May. 17, 1938. w. w. PoTTER ET AL MACHINE TOOL Original Filed June 4, 1931 ll Sheets-.Sheet 3 @mum FIG. 3

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ATTORNEY May 17, 1938.

w. w. POT-rea ETLAI.

MACHINE TOOL v1i sheets-sheet 4 original Filed June 4, 1931- May 17, 1938.

w. w. POTTER ET A1.

MACHINE T001I original Filed June 4, 1951 11 sheets-smet 5 FIG] VENTORS ff W@ @L TTORNEY Original Filed June 4, 1931 w. w. POTTER' ET AL MACHINE TooL l1 Sheets-Sheet 6 NDEX WTTORNEY May 17, 1938. w. w. POTTER ET AL MACHINE TOOL Original Filed June 4, 1931 1l Sheets-Sheet 7 3 FIG. Il- 63 Clif/CA 1Y0/'0R ATTORNEY May 17, 1938 w. w. POTTER ET AL MACHINE TOOL original Filed June 4, -1931 11 sheets-sheete .vow

T ,ET/m4 ATTORNEY W MQW,

May 11, 193s. W. w. POTTER ET A1 v2,11'831221 y MACHINE TooL original'Filed June 4, 1951 11 sheets-sheet 9 FIG. IS

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W/ATTORNEY May 17. 1938. w. w. POTTER ET AL v2,118,024

MACHINE T001.

Original Filed June 4, 1931 11 Sheets-Sheet 1C .u mmm with wm Nmm May 17 .1938- .W. w. POTTER ET AL. 2,118,024

MACHINE TooL l Original Filed'June 4, 1931 1l Sheets-She??l 11 SPIHDLE Moron Sol.. -fvvsole/vow SV: SWITCH S*- STOP INVENTO 5 G: so 4 MWDOW, 71m? wm H i #f1/vo BY mp0s ATTORNEY MACHINE TOOL' wuusm Wallace roam and Myron 's. curas, Pawtucket, B. I.; said Curtis assigner to said Potter Application June 4,1931, Serial No.` 542,156

. i sz claims, Our invention relatesto metal working machines of the type which have work carriers and enacting tool slides or holders mounted tor periodic movementrelative to one another for .bringing .them into andout of wrkingrelation,

and for the performance of the desired operal tions on the work pieces.l As one embodiment of the inventionrw'e show such .a machine of the types of'machine-tools.v Among the features of the present invention are the following:

do. not limit-theinvention to' that particular em- 1. Tool slide guiding means that -assure easily' our invention are suitable and useful in iotlierV attained accuracy of the alignment of tool slidek and spindle. landindenite maintenance of the same; the alignment of spindle and tool slide is not affected by wear of the spindle carrier conse'- quent on indexing, or from-the action of ymeans used for locating and binding the spindle carriery yin its various indexed positions, andlis not, ailected by the"distorti\on of other machine elements, by uneven foundation, heat, etc.

spindle andv the tool slide, with the result that 'the' wearing ualities are improved and there are fewer cha ces oi'. mlsalignment.

ed by iorce'applied to move the slide that is .centrai in respect to the various tool positions; access of all dirt, etc.. is-excluded: the various -thrusts are vself-supported and adjustment'` is .4. The 'angular alignment oi' the tool slide with v.the spindle is simple, positive-and easilyadjustiibley so that theoriginal alignment can .be easily .attained and maintained. 45' 5. So mounting and driving cross slides as to pe t cross slidesbeinglapplied at any or all 2. So'locating and binding the spindle carrier carrier and the tool slide, and doing this by means that require the minimum of joints between the.

3.' Feeding or traverse of the tool slide is eiletspindle stations with the minimum of connections and also to permit of the cross slide feed, usually aI cam, to be diilferent for the diilerent cross 50 slides and to beeasil and conveniently removed and to4 permit variat on ofthe relation between the various 'slides to be conveniently eilected and by simple means..

6. lA clutch for clutching and decluitching each 55 spindle as it arrives at a loading station.` by.

7. The .minimum of. parts .for operating Renewed July 9. 1937 (ci. zei-ss) l which the. clutch teeth are brought to approximately equal peripheral speeds before meshing, and the spindle at vthe loading station canbe clutched or declutched by hancl5-v A the .5,

chuck at the loading station and-an operating mechanismthat is automatically thrown in and out oiA mesh as the spindle comes to and leaves the loading station.

A8. So supporting the spindle carrier while in- 1o4 dexing that the weight is taken upon anti-friction l bearingsV while indexing, and when indexedv )a v positive metal-,to-metal contact isimade between the' spindle carrier and its housing.

9. `So supporting and driving rotating tools in 16 the tool slide, that said tools may be easily applied at any fspindlestation, and thespeed maybe easily and conveniently varied and the drive be independent of the driveof the main spindles.

10 Advantageoussupply .of cutting lubricant to the revolving tools oi? the tool slide;

11. So driving the members oi' a machine toel organization that eachV has its individual driving motor and the-motors are interlocked and controlled and thus produce ai greatly simpliiied g5 organization compared with prior machines where jthe various machine members are geared to and driven from one source o1' power.

Other 'characteristics an`d` advantages in me chani'cal construction will be seen and appreciated so from an 'examlnatlong of the accompanying drawings and the'deaued description thereofv which` follows. Figure 1 is a front elevation of a 'machine em' Insuch drawings:-

bodying-our invention; t s 35 Figure 2 is a longitudinal section substantially on the center line o! lFigure 1, 'with some displaced for clarity oi' illustration; l .Figure 3 is an endelevation with the door re- ,movedyK-.y ,v- V` Figure 41s a cross section on line I-l of Fig3' .showing on an enlarged scale the spindle clutchingbmechanism; f y Figure 4a is an end elevation oi' part of Fig. 4; Figure 4b is a detail viewofthe rod Il of Fig. .4 ina dinerent position from that `'shown in Fig. 4; Fig. 5 is an elevation partly in section oi 1 oi the vtool slide end opposite that shown in Fig. 3;'

Figure 6 is a cross section substantially on the [y 4 on the line switch with the cover removed and parts in section;

Figure 15 is a front elevation of the index limit switch with the cover removed and parts in section;

Figure 16 is a diagrammatic view of the switches, contactors, interlocks, wiring, etc., that provide' the electrical control;

Figure 17 is a simplified diagrammatic view of the circuit arrangement more completely ill lustrated in Fig. 16.

The invention consists in whatever is .defined by or is included within the terms or scope of the appended claims.

General construction The main frame and housing (see Figs. 1, 2 and 3) include a bed or base 50 and a spindle carrier housing 5I, a gear housing 52 and a rear housing 53 aligned horizontally and firmly bolted to the base. These three housings are bored horizontally and in axial alignment, the two housings 5| sponding to a headstock and the housing 53 spaced therefrom and answering to a tailstock. A compact, sturdy and sightly framework and housing are thus provided. 'I'he carrier housing bore contains a cylindrical spindle carrier 54 closed at one end and open at the other end which latter is closed by-cover 55 which forms a rear end wall therefor. Opposite portions of these walls of carrier 54 are bored toreceive and support in suitable bearings, spindles 56 which, in the machine shown, are six in number, each with These spindles are located equidistant from the center of the carrier and equidistant from each other, and the carrier 54 is indexed through onesixth -of its circumference in a step-by-step manner hereinafter to be described so that the spindles are successively brought to a station at the front of the machine which is hereinafter called the loading station. As each spindle approaches the loading station, it is automatically declutched and braked, and after it leaves the loading station the brake is automatically rc leased and the clutch engaged.

Spindle and spindle gearing and 52 being joined and correits driving and clutching mechanism.4 'axial 0f rod 12- line 8-8 of Fig. 2 showing the spindle carrierv Also keyed to shaft 59 is collar 6| (see Figs. 2 and 4)' carrying in radial holes a series of pins 62 which are impelledoutward by springs 63 but which are held from falling outof their respective holes by a plate 64 in each case.

Referring to Figs. 2 and 4, it will be seen these pins coact with an internal cone 65 formed in a flanged rim or extension of pinion 58. When pinion 58 is in its extreme left. hand position and unclutched, the pins do not touch the `cone, but as pinion 58 is moved tothe right to clutch, then the internal cone bears on the outer ends of the pins 62 with enough friction to impart rotation to pinion 58. Further movement of the pinion to the right causes the teeth on the pinion to mesh with the teeth on clutch 50 and when these teeth touch, pinion 58 is running at ap-` proximately shaft speed from the frictional drive given by pins 62 and, therefore, there is no clash of teeth in clutching.

When pinion 58 is in its extreme left hand or vunclutched position, its internal cone 65 contacts with an external cone 69 on the stationary or fixed sleeve 10 and thus, as the teeth of pinion 58 and gear 51 are always in mesh, actsas a brake to hold the spindle when its rotation is stopped. The pinion 58 is shifted axially on its shaft 59 for the above stated operation by yoke 1I and yoke'rod 12. Yoke and rod are shown out of place in Fig. 2 for clarity of illustration, but shown in Fig. 4 in proper relation with pinion shaft 59.

Rod 12 slides horizontally in bearings in end wall of carrier 54 and carrier en d plate 55. Fixed to one end is a pin 13 that coacts with a cam 14 (see Figs. 4. .4b) which is fastened to housing 52 and therefore stationary. As spindle carrier 54 indexes, pin 13 travels over cam 14 and rod 12 is thereby pulled against the pressure of spring 15, thus declutching pinion 58 from clutch 60, and, as carrier 54 again indexes, cam 14 allows rod 12 to be pushed in the opposite direction by spring 15, thus clutching gear 58 and clutch 69. To allow backlash for wear.on brake 69 when clutch rod 12 is pulled by cam 14 to unclutch, yoke 1| is allowed a certain amount of movement along rod 12, this 'being possible because it is heldto said rody by pin 16 which extends diametricallythroughA a slot. 11, longitudinal or Such pin is normally held against one end of the slot by a spring 18 and plunger 19, but spring 18 yields when pinion 5l and brake cone 69 come in contact. 'This gives a cushioned, braking effect and allows for wear.

Manual clutching and declutching pinion 5l while in the loading station is provided vby having the central'portion of cam path 14 formed in the rod (see Figs. 4 to 4b) which rod `is slidably `spring 8| which `is considerably stronger than spring 15, but it may be -moved against such spring in the direction to clutch pinion 58 with clutch collar-60 by hand lever. 82 (see Fig. 1)

through ,shaft 83. link 84, connecting rod Il, link 8 8, shaft 81 and yoke 88 whichl connects with rod 80 (see Figs. 1 and 4). 'Ihe pin'18 is in the part oi' the cam path in the side of rod 89 vwhen this action takes place. y

Shaft 59 is supported in carrier 54 by suitable bearings in the carrier end and coverV plate, and has keyed toits outer end pinion 89 lwhich meshes with and is driven by a central gear I1 mounted' by suitable bearings on a sleeve Il which is supported by the carx'ier endplate l5.

spindles' are driv 'A |22 is removably keyed change pinion |21 v gear 'housing 52.

`Aammini v As there are six spindles l2 and'shafts l2 in.

the carrier 54 located equidistant from the center 'to shaft |29 which is also-supported by suitable bearings in gear housing 52.` Also removably keyed to shaft |29 is pinion |32 which meshes with and drives gear I2I, removably keyed to shaft |22, also supported by suitable bearings in To the end of shaft |22 is keyed pinion |22 which meshes with gear |24 which is an yintegral part of gear 81. Bearing plate 52a is removably xed to gear housing 52 and upon its removal, 'gears |21, |28, |22 and |2| may be removed" and interchanged and thus change speed drive connection is provided between motor |22 and central pinion 81.

Spindle carrier indezng andl locking Secured centrally to and projecting axially from `the spindle carrier towards the tail-stock end of the machine is-a hardened steel slide supporting tube 22. It is solidly attached to the carrier by a flanged collar shrunk-and welded thereon, and though'the flange of which bolts 9| join it tothe carrier end. Spindle carrier 54 and slide support 82 are thus, in effect, integral or one piece. At its other or tail-stockend, tube 29 'is stoutly supported by a bearing 22 in housing I2. `Encirciing and slidably supported by tube 89 is tool slide 92.

For indexing the spindles, carrier end plate 55 isvprovided with equi-spaced slots 24 correspond- -V ing with all of the stations of the spindle carrier (see Figs. 2 and 1 0) with which a roll 25 on index disk M interacts as disk 92 revolves about shaft 21 so that carrier 54 is rotated Vg of its cycle of movement for each revolution of disk 96 after the fashion of the well-known Geneva motion. Disk $4 has a-,worm gear 92 fixed to one side, meshed by worm A20 on a shaft Ni connected by coupling |22 with its own driving motor 22. Carrier 54 is thus indexed by its own motor, (see Figs.`9 and 1Q).

Indexing disk 92 has in. one side (see Figs. 2, 3, 9. and 10) a cam groove |22 with which a roll .m' on am llames. 'rm m is keyed to .l manille wwnicnis also' keyed 'shemale part |21 of a toggle arm, the female part |02 of said arm being connected by link/|22 vwith one end of a wedge lil' so' that movement of arm |05 about.

the axis er shan se um 'longitudinal movef' by -acemateiy nx and einen' in ineeied position. l Preferably the-spin endsy contact with hardened 2 #Prints nient of wedge ill'. "The connection`- between arm III and wedge lilisyieldable a spring :ill ispla'ced between thetwoparts |l1I and |22 of 'the toggle arm. v Movement of this we dge under togglethrust pushesdown pins ||2, slidabl'e in bushings H2 against the .p nessure of ||4. .|,|2.are two in number and are apart to bear at separated points upon the flattened sides of thecarrierv .theresteel disks lilgnxed wthef'emier peripneny.y

The powerful -eiuiy opposite' =side vfrom we wedg mathe carrier against the housing li.. When by movement of lever Ill in the op lposite direction the wedge is withdrawn. pins ||2 V are caused to move away from the carrier by springs I i4, thus releasing the seating pressure on .carrier 54 and leaving it free to turn for indexing.

Pins H2' nd wedge III are relatively so located and fo ed that' if for any reason springs ||4 should not lift pins ||2 when the wedge is retracted, the, rotation of carrier 54 would push pins ||2 out of the way as the retracted wedge provides space for them. The wedge and pin device makes a positive andy simple means for locking'v and binding the carrier. Cam |22 is so located on disk 96 in relationto roll 26 that in `one rotation of disk 96 the wedge III is first withdrawn: the carrier 54 is then indexed andwedge i|2 is then seated, and as these indexing and locking operations are performedby the same member (disk 96) there is no possibility of any mishap.

, When binding pressure on carrier I4 sreleased by thev retraction 'o f wedge il, the carrier 54 is supported on rollers ||2, mounted on shafts ||1 (see Figs. 2 and 8). 'Y 'I'hese shafts are eccentric i and eachhasaixed arm H2, connected by rod H9 to the other arm, the armsstanding at the same angle so that by movement of the rod inv one direction; there is always a tendency to rotate both shafts ||1 so4 that rolls H2 will press againstv the bottom of-and support carrier I4. 'Ihe rod Il@ `is so moved by a spring |22 that'lit bears at one end against web i2| that is part oi'- housing bi. The strength of spring'l24 and the various leverages' involved are so computed that spring will lift carrier 54 so that it'ls free 'to rotate on the rolls ||4 and. thereby prevent wear in its seating, but, of course, .under the wedge pressure exerted on pins H2, will seat carrier 54- inits housing against the. pressure of spring |22.

' Tool slide Referring w rigs?. and mit will be seen thatV tool slide' isslidably mounted by adjustable hearings Vori'tube 29 and has a laterally projecting head |26 surrounding Vslidably stationary bar |31 parallelwith the tube 22 and supported by'housings 5| and 52. Bar |21 is provided with bearing. plates |22 von opposite sides with which,

gibs '|22- in head |26 slidably coact. Thereby slide 921s prevented from turning by its connection with bar |21. The tool slide 22 is provided with six substantially horizontal bores |42 which are respectively located in line'with the axes of the spindles 52 and in which tool heads 242drills, etc., may be inserted. The tool slidefsee 6) is also provided with Asix faces i4| on whlchltools may bexed. It is also bored out in two diametrically opposite corners for stop rods |42, one end of which is 'fixed in rear housing 52 (see Fig. 2)

-which stop rods-are free to slide through the bores 'sin tool slide 92. Threaded on the' end of stoprods |42 are adjustable stop collars |42 solocatedthat when tool slide 22 reaches vits extreme'frward position, it abuts against -these stop-collarsfand thereby is brought toea positive'stop. These collars may be reached Power is applied .to backend forth by bar |45, Fig. E.' which is within for adjustment by removing `andv concentric with tube 22 and theconnection v with which is' by a animale 14s, adjustabi along' said rod. f Surrounding tube 22 'and'connnedhe' tween side shoulders in slide 2 2 but free to rotate, is ring |41 yradially bored to recel-ve bushings |42 in which are inserted pins |49. These pins and bushings project through-longitudinal slots |50 in tube 89 and the inner ends of the pins enter a end 15,5 of the pinion. Thusthimble -|46 can be' rotated with relation to bar l|45 and as it is threaded on said bar its longitudinal position along the bar may beadjusted. Thimble |46 is normally prevented from rotation with respect to bar |45 by clutch |56 slidably keyed to bar |45 and Whose teeth engage with corresponding teeth on gear |53, when forced in engagement by nut |51. By loosening nut |51 coil spring |58 between gear and clutch forces clutch |56 out of engagement with gear I 53 and the latter may be turned.

Bar |45 is kept from rotating by .roll |59 on the end of stud |60 placed in a diametrical hole in bar |45, which roll is'in a longitudinal groove in a block |61, in a horizontally projecting arm |62 located in holes in housing 52.A Said arm |62 is kept from rotating by pins |63 (see'Fig. 3) fixed in'gear-housing 52 Side thrust on bar |45 is takenl up by rolls |64 supported in bar |45 by radial pin |65 and bearing on plate |66 (Fig. 3), firmly xed in arm |62. Pin |60 is `revolvably held in -bar |45 by ball bearings |61 and |68 and has its end formed into a cam rolll |69 which runs in a groove in cam |10 bolted to the periphery of cam drum |1|. As cam drum |1| revolves, traverse motion corresponding to the shape of the groove in cam |10 is imparted to bar |45 and thus to tool slide 93. 7

For taper turning the slide ,93 as it reciprocates may be given a slight rotary motion about its longitudinal axis las by making the surfaces of the bearing plates |38' at an angle or obliq'ue to the longitudinal axis of bar |31.

l Y Tool slide cam drum Cam drum |1| (Figs. 2 and 3) is free to rotate on a horizontal stud |12 ilxedv in bushing |13 firmly fixed in gear housing 52. On the outside by pins |18 to drum |1| for rotating drum |1| by vworm gear |15. The end of drum 1|, opposite worm gear |15, is provided with a roller thrust bearing- |11 which abuts against bushing |18 i screwed ,in plate |19 bolted to gear housing 52 and, thus, longitudinal or axial movement of drum |11 in that direction is prevented. This end bearing takes the thrust generated in returningl tool slide 03' from Working position. Longitudinal movement of drum |1| in the other direction and the thrust generated `by tool slide 93 moving to its working position, and also the thrust generated by the ltools in cutting is taken by thrustl plate |80, bolted to worm gear |15 and coacting with roller |8| held in arm |62 by roller bearings |82. vArm |62 abuts against thrust platey |83 which is screwed on bushing 68, bolted to and therefore an integral or a unitary part .of spindle carrier 54. 1t will be seen that the thrust generated by tools 'carried by tool slide 93 against the work in spindles 56 is so taken4 care of or compensated for that in .that respect the mechanism is self-contained.

Spindle carrier 54 is held against longitudinal or axial movement by thrust bearing |81. This may be adjusted by threading bushing |88 in rear housing 53, and by adjustment of this bushing all longitudinal movement of carrier 54 is taken up through bearing |81, tube 89, housing 54, plate 55, bushing 68, collar |83, sleeve |62, roller |8l, plate |80, Worm gear |15, spider |14, drum |1|, thrust bearing |11, bushing |18 and plate |19.

Feed 'gearing Worm gear is rotated by worm |89 keyed to shaft |90 (see Figs. 2, 3 and 13) journalled in gear housing 52 by suitable bearings, and has keyed to it gear |9| meshing with pinion |92 keyed to shaft |93. Thus drum |'1| is rotated at a fixed speed relative to shaft |93. Shaft |93 and, therefore, drum |1| has two rates of revolution, one a slow speed for feeding, which speed is in direct relation to the spindle speed, and the other, a Afast constant speed for idle movements. Either of these speeds may be automatically given to shaft 93. Slow speed for feeding is imparted to shaft |93 (see Figs. 2, '3 and 12) from spindle drive gear |34 which is an integral part of gear 61 and which, therefore, rotates at a fixed speed relative to that of spindles 56. To this end gear |94 meshes with and is driven by gear |34 and is keyed to one end of shaft |95 journalled in gear housing 52 by suitable bearings. To the other end of shaft |95 is removably keyed pinion |96, meshing with gear |91, removably keyed to shaft |98 which shaft is journalled in gear housing 52. Access to these gears for changing may be had by removing plate 52h, and by changing these gears the speed ratio between shafts |95 and 98 may be varied. Integral with shaft |98 is worm 99 meshing with and driving'worm gear 200, that rotates loosely on shaft |93 and drives clutch head (Fig. 13), also rotating loosely on shaft |93 by a well known ratchetroller device 403 so that gear 200 drives clutch head 20| when it is revolving faster than the latter, and when clutch v head 20| is revolved faster than worm gear 200,

204, and when so clutched shaft 93 is either driven by the spindle drive gear |34 at a speed in direct ratio to the spindle speed or at a fast speed for idle movements by motor 205 which is directly connected to shaft |93 by pinion 206 and gear 201, and when energized revolves shaft |93 at a comparatively high speed, clutch head 20| running away from Worm gear 200 by its ratchet roller connection if clutch 202 is engaged.

' When clutch head 20| is declutched from shaft |93 by friction clutch 202 and motor 205 is deenergized, shaft |93 and, therefore, drum |1| are stationary and it is necessary to operate this clutch only when the feed cycle of the machine is stopped, or when the tool slides are to be fed manually. 'Ihis latter is necessary as the manual feed is accomplished through the motorv 205 which may be run in either direction and which, if run l in the reverse direction with clutch 202 engaged.

would jam the roller ratchet device 403 by which worm gear 200 drives clutch head 20|.

.Clutch 202 is, as previously stated, operated by clutch yoke 203 through thimble 204 and clutch yoke 203 may be automatically operated by dog 264 (see Fig. 3) fixed to cam drum |1| through .finger 265 of lever 266, pivoted on stud 261 and connected by connecting rod 268 with yoke 203.

' this motor, dog 264 acts on finger 269 on lever' 266 Drum 111 can now only be revolved by motor 206 and as it revolves on the fast motion driven by and, through the same connections, throws in clutch 202.

Clutch yoke 203 may be operated by handlever 218 (see Figs. 1 and 3) keyed to shaft 211, to the other'end of which is keyed link 212 which, by

lconnecting rod 213 and link 214 keyed to, shaft l 216, operates yoke, 203 which is also keyed to y l. shaft 21s'.

' lthe entrance of dirt, chips, etc.

Cross slide construction Referring to Figs. 1, 2 and 7, it will -be-seen that forfacing c uts and the like, cross slides are provided as shown, four in number. It is apparent lthat more or less than four may be easily and conveniently applied. As all cross slides shown are alike in construction and operation, description of but one is necessary. Bolted to carrier housing 61 is crossvsiide base 209 which is adapted toreceive a single cross slide, as shown bythe illustration a on Fig. '7, but these cross slide bases u may bev constructed in tliemanner shown at b,

Fig.7, so as to receive two cross slides on opposite faces thereof in cooperative relation with the spindle canier 64. Gibbed in suitable ways on this base 209 is cross slide 210. Longitudinally adjustable in slide 211i is block` 211 in which is rotatably mounted cam roll stud 212 so that the inner end of stud 212 engages a'grqve in the cylindrical cam 213. Block 211 may be longitudinally adjusted in slide 210 `by adjusting screw 2'14, and when so adjusted isrmly held in place. A

lstop .screw 215, adjustably xed in base 209, en-

. cam 213 and when the clutch plates'. are in mesh.

I 4:so

` for Vthe purpose cam 213 is driven'by worm gear 218. By unscrewing bushing 2 21, which is screwed in end plate 222, it abuts against collar 223 "on shaft 211 and its continued movement causesit to pull out shaft 211 and thus pull cam 213 out of engage-- mentl withfwormgear 218.y The relative positions of cam 213 and fform gear 218 may'now be altered of timing. Cam 213 may be removed for the purpose of substitution; o r the like, a slot l(not,sl1own) being provided in the end off' cam 213 and cam plat 220 to allowr cam roll 212 to clear' itself. The vthrust of slide 210 in feeding direction is taken by anti-friction bearing'224, and thrust in'the opposite direction ls taken by thrust -washers 225. Y Worm gear 2-18 is 'driven by' buil gear 226 through intermediate gear 221 and gear 229, which is' keyed to' shaft 229, rotatably supported invbase 209 'and .carrier housing 61, and K which shaft 229 has'a worm 230 meshing with worm gear 218.` In a similar way all cross. slides receive their motion from 'bull 'gear 226 (see Figs. 2 andA '1); With respect to the type of cross slide base b, shown in Fig. 7, .where the cross slides thereon are in closer proximity, the shaft 229 carries the gear 221 which is in mesh withy bull'gear 226 and the worm 230 on the shaft 229 engages, on opposite sides thereof, the worm gears 218 of the cross slide mechanism of the two cross slides mounted on the single/base. This construction is compact and. desirable where it can beused Y as it conse rves space and eliminates operating Bull gear 226 is carried by and rotatably mounted upon lthe periphery of the end `plate 66 of the spindle carrier 64 and is driven from shaft 193 (see Figs. 2, 3 and 12) through. worm 236 and worm gear 231 keyed to"shaft 236 journalledin gear housing 62.` To one e'ndof shaft 238 is keyed pinion 239 meshingwith and driving bull gear 226. 'I'he ratio of -gearing between as the ratio of'gearing between shaft 193 and cross slide cam drumK 213, and, therefore,"each drum makes a revolution in the same time, and

one revolution is a working cycle of the ma= chine. A

Rotataple tool holder cmmmcton It .may be advisable or desirableto have tools shaft 193 and feed cam drum 111 is the same` carried by tool slide 93 for yoperating on work I carried by chucks366 on spindles 66, and which revolve in doing their work and are not station,-

ary. Referring to Fig. 2, it will be seen Vthat provision ismade for such operation of tools by` mounting in each ofthe apertures 140 of the tool slide `93 a sleeve 240. Since the 'construction and operation of lthese sleeves is the same in all instances, only one will be described. The sleeve 240 has a longitudinal, but-not a rotatable adiustment in the aperture 140 and when ,so adjusted it is xedly clamped. Rotatably tight chamber 244 in a bushing 246 fixed inv sleeve 240. Fluid may be led to chamber 244 from pipe 246 through port 241 and thus a uid.

cutting compound, for example, may be`forced to the outer end of spindle 241 through hole 2,42 from a source of supply not shown.

The rear end 248 of spindle gitudinally in sleeve 249 journalled in bearings inrear housing 63. Keyed to sleeve 249 is gear 260 driven by gear 261, either directly or'through v zu is caste-usted i that it may be rotated by, but free to move lon` an intermediate 262 (Fig. 5) It will bejseenthat by providing suiiicient number oi intermediates 262, a sleeve 249 rotatable by gear 261 may be provided for each spindle station. -Gear 261 is.

keyed'to shaft 262`journalled in rear housing 53 and to which shaft is removably keyed gear 254 meshing with-pinion 256 removably keyed to shaft 266, also journal! in rear housing-,63.

`Access to gear 264 and p ion 266 `forchange may be had by removing plate 25,1 and these gears may be changed for the purpose of altering' the rotativev speed of sleeve 249. Keyed toVV shaft 266 is worm gear 268 meshing with worm 269 on shaft 260 driven by -its individual motor 261I through pinion- 262 and gearv263 (see, Fig. 5)

and therefore sleeves 249 are drivenl by motor -261-at a speed which may be varied by means of change gears 264 and 266 for the purpose of rotating a tool, or in some cases work carried A.For chucking, ,is provided a power-operated differential chuck 866 (Figs. 1,2, 7 and 8) at the front end of each of the spindles 66, which chuck has extending rearward through thespindie a shaft 361 on the back end of which is a clutch `face 358.l As-a spindle carrier 54 indexes to move a spindle 56 to the loading station, the shaft 351 is brought4 in line with a motor 359 (Figs. 3 and 11) supported in gear housing 52,

on the shaft of which is' keyed a driver 360, provided with external gear teeth which mesh with internal gear teeth on a sliding clutch sleeve 36|, this clutch sleeve being provided with a clutch face 362 which can be made to mesh with the clutch face 358 on the chuck operating shaft Clutch 36| is thrown in and out of mesh with clutch face 358 by a cam 363 on the periphery of the index disc 96. The cam acts on a roll 364 on one end of yoke lever 365 pivoted on stud 366, the other end of said yoke lever actirig on sleeve 36| to shift the same. Aspring 361 always tends to throw clutch sleeve 36| into mesh with clutch face 356 and it is allowed to do so when indexing disc 96 is in its stopped position, and^when in mesh, chuck 356 can be operated by switching into circuit motor 359, by means of switch 368 (see Fig. 1). As the index disc 96 starts its revolution, cam 363 acting on cam roll 364 withdraws clutch sleeve 36| 'from engagement with clutch 358 and holds it Withdrawn during the periodof indexing of the spindle carrier 54, and at the iinish of the-index allows it to be again forced into mesh by spring 361.

Electrical control Because of its exibility, or adaptability and dependability, we utilize electricity for the con trol of the members of the organization constituting the embodiment of our invention and.,

ifo'r indexing the spindle carrier should be held inoperative except when the tool carrying slide 93 is at a predetermined' position with respect to the spindles and itis also important that the slide motor 205 for the fast motion of the tool slides be inoperative except when the spindle carrier is stationary-'and, therefore, when the index motor 99 is stationary with aILindexing functions completed. 'Ihis interlocking of functions is taken care of by limit switch 386 which is operated by a fixed dog 381 o n index disc 96 and limit switch 291 whichis operated by a iixed dog 299 on slide drum |1| (see Figsyl, 3, 10, 14, 15, 16 and.A 17).

. The dog 381 operates the plunger 3 |9 of limit' switch 386 through levers 323 vege-inet the pressure of a spring 324 which normally urges the plunger3|9ina right hand direction, as shown in Fig. 15, through the medium of collar 352 pined located by shoulder 335, collars 33| and 332, and

- springs m and mj that when plunger m is operated on by dog381 and plunger 3| 9 is in the position shown in Figs. 15, 16 and I7, contacts 323 and 321 are closed and contact 325 is open.

As dog 391 Ais moved out of engagement with -nger 323 and plunger 3| 8 is acted upon by spring 324. contact 325 rst closes, contact 326 then opens, followed by the opening oi.' contact 321.

In a converse manner, when dog 331 acts on lever 323 to move plunger 319 against the pressure o! spring 324, contact 321 iirst closes, then contact 326 closes, followed by the opening o! the contact Limit switclfi 291 (see Figs. 14, 16 and 17) has a plunger 298 operated by dog 299 on slide cam drum lli, through plunger 333' and lever 334 oivoted on pin 335, against-the pressure of spring 349 which acts on plunger 298 through collar 343. On plunger 298 contact disks 336, 331

and 338 are looselyk mounted, positioned by springs 339 and 340, shoulder 34| and collars 342"'and 343 on plunger 298 so thatwhen dog 299 pushes plunger 298 against the pressure of spring 344, contacts 331 and 338 are closed and Contact 336 is opened. As dog 299 moves out.

of engagement with kplunger 333, plunger 283 is pushed by spring 344 to iirst close contact 336,` then to open contact 338,.and then to open conit is obvious that if-a motor running at its synchronous speed is deprived of power'orcut out of circuit that the inertia of the armature ning or coasting beyond the point where it is de sired to stop, and it is important that this overrun be eliminated or reduced to the minimum.

and other rotating parts will cause an over-run- With alternating current motors the practical way of eliminating this over-run is by plugging or, in other words, at the instant o1 cutting out the current from the motor, to apply a reversing current to the motor, this reversing current being broken immediately after the motor starts to actually reverse the direction of rota-l tation of; its amature. plugging switches for both theindex motor and the slide motor and it is obvious that such 'a plugging circuit could also be applied to" the spindle motor, the high speed drill motor, or any of the motors used if such was desirable.

We illustrate the electrical circuit in Figs. '.16

and 1 7, Fig. 16 being an actualwiring diagram of the machineand Figt 17 being a so-called simplied Wiring diagram; Like numbers refer to like elements onthe two diagrams. Figs. `16

We, therefore, provide and 17, and for easy understanding all interlocks or switches controlledby a relay bear the number of that relay with a subenumeral. It is understood that arelay consists of a solenoid opf erated switch or switches, which switches are called interlocka, but. of course, any othersiml -which means that the 'swtchis opened when v the solenoid is not excited and closed when the solenoid is excited, -and normally closed, .'which means thatthe switch' is. closed when the sole noid is not excited and openwhen the vsolenoid is excited.' In Fig. 17' a normallyvopen inter-- lock is shown by two parallel' vertical lines with noconnection between them, and normally closed interlock isshownby twoparallel .verucal lines connected by adiagonal line.

We further provide in the electrical circuit a number of hand operated switches, preferably of the push button type and dog operated switches. 'Both the hand and dog operated switches bear of :ne dog operated switches.. uw if' une handze 1 5 drill motor 29| except when the |22 is operated but it is sometimes desirable to push button or' the dog operated switch is nor-` mally open, itcarries a sub1etter.G and if it is normally closed it carries a sub-letter S. For example, a normally'open hand operated push button controlling solenoid Illwill carry the number SI1-GIL and va normally yclosed hand operated push'button controlling the same solenoid will carry the number 3|1-SH. For simplicity and clarity, we also letter lcertain termiand it is understood that terminals having the same letters are always normallyj'electrically incircuit. f

Asihereinbeiore described; we also provide a hand lever 21|) by which shaft |93 can be conwith worm gear 209. When connected with said worm gear the machine is said to be under autounder manual or automatic control, we will first describe it. a Spindle control The main spindle motor |22 is controlled through a contactor `216, of known construction, from push button station 211 (see Fig. 16). Current flows from main line wire 218 to connection A on panel board 219, thence to connection Av on push button -panel 288 (see Figs. l and 16) and thence to connection. A 'on push butt-.fon 211. By depressing button 28|-GH connection is made between A and b and current flows back to connection B on panel 219, thence to connection vIB on contactor 219 through solenoid 28|, .thermally operated vsafety-device 283 to thermally `nais and connections, pagticularlyon Fig,I 16,

, nected or disconnected by means of clutch 202 I operate the latter without the former which may b e done by opening manually operated switch 299.

y) automatic control As hereinbefore stated, by operation of `han lever218, switch 381e. may be thrown into the position shown on Figs. 16 and l17 connecting live line wire 218` through connectionsn withj the automaticcontrol line wire 2`|8a through ter` minals H. Accordingly all` connections connected-with the live line wire 218 and' therefore all connections A and H are alive and the machine is in condition for automatic operation. I

The automatic cycle of operations is as follows:

Assume the tool -slides to be stoppedat the extreme rear positions. Dog 299 is so located on the slide drum |1| that at this time switch plunger 298 is fully thrown by the dog, occupying the positionsshown in Figs. 14, 16 and 17 and as the spindle carrier is completely indexed, dog 301 on index disc 98 will be in s uch a position that switch plunger 3|9 is fully thrown by dog 391 to the positions shown in Figs. 15,: 16 and 17. 'I'he operator having finished chucking a piece at the load1 ing' station presses reset button 3||l (see Figs. l. 16 and 17) completing a circuit through solenoid 345 it the spindle motor is running so that interlock 281--2 is closed,"but if the spindle motor is not running this interlock will be open and no circuit will be formed.V This is desirable as slide operation should not be started unless the spindle motor isrunning.

Energizing solenoid 945closes interlock 34e-l, thus completing a holding' circuit through solenoid 3.45 through closed switch 321' so that when the operator `allows switch 8||| to open solenoid MBremains'energized. Energizing solenoid 349 also closed'interlock '945-2 forming a circuit operated safety device'283a of the high speed drill motor 26|, thence to connection F on panel 289 land back to the main line wire 284, thus completing 'a circuit that jenergizes solenoid 28| whose plunger or core operatesthree-way switch 285 to close the latter and start motor |22. Energizing .connected with B through limit;v switch zal-SH.

and thence lbaci; to connection B in contactor 218 -and through solenoid 28| and safety contacts '283 and 289a to main wire 29|. This provides so that holding current ows through connection` I through solenoid 3H through switch 321 and-v overload rene: switch als if the interlock :sl-2

is closed, which it will be if the spindle is running;

Therefore, the index motor cannot be started unless the spindle motor isrunning Energizlng solenoid 3|4 operates theLthree-way switch plunger 2|6- to close the ahead circuit to fas the index motor 99 and-start. the same in the di-l rection' shown bythe arrow on Fig. 16: The energizing of solenoid 3| l also opens normally 'closed interlock 3 |4| which prevents current from going through the starter solenoid 3|1 of the slide operating motorswitch 293. Therei'ore, the slide motor cannot operate while the-index motor is a closed' holding circuit so that when button 2M-GH is released and the4 connection between A and C on panel 280 is broken, this Iholding cirena wiil `keep switch; :as closed.v -fro stop-- motor |22 itis only necessary to break this holding-circuit which may be done .by depressing but.-

broken in-,case of Voverload on either motor |22 or motor. 29| b y thermally operated safety .switches thretore, motor 28| willstart and stop withrno- 'In ofthe nigh speed drm motor :si vare ,Floodedboth motorsJ will stop.

It is never necessary to operate Overnie' ,nigh speed tor |22. Also, ii' either the mainvspindle motorV spindlek n iotor,v

- f .938, and also 'closes interlock ISU- 2, but as intertwink-SH. 'I'hisholdlngicircuit may alsov be switch 492 closes, but as normal vleek 2li- 9 has previously been opened by the operating. s

The energizing of solenoid 3| I closes normally open interlock Ill-2, completing a circuit through solenoid 958. This excitation of solenoid 250 closes interlock S50-I 'which completes' a. holding circuit through coil 359 through switch terlock IEW-1; I

When the indexing motor 99' starts, plugging ly closed interenergizing lof solenoid'3l4 no circuit is formed.

This plugging switch is of well knowngconstrucnoid 28| ofthe main (spindle contactor 218 and,

tion and vis irictionally revolved by the shaftl of the motor, which it controls, in such amanne'r that the switch is closed by the ahead rotation ofthe motor, is opened by the reverse rotation ot the motor and will open itself by gravity if. the

motor is stationary.

When th index motor starts index plate 96 revolves and dog 301 leaves plunger 3|9, thus allowing spring 324 to" operate plunger 3|9, i'lrst closing switch 325 which completes a holding circuit through the index motor starter solenoid 3|4 vv5 l(Figs. 16 and 17). Further movement of plunger 3|3 opens switch 326 preventing any current now-ing through the slide motor starter solenods 3| 1 or 32| while index is taking place, thus preventing operation ofthe slide duringv indexing.

V Further movement.` of plunger -3|9 opens switch 321- breaking the, circuit through solenoid 345,

thus'opening holding circuit interlock 345| and "also the starting circuit interlock 345-2 forthe index motor solenoid 3 4. But as a holding circuit .-16 has already been Aformed through solenoid 3| 4,

as hereinbefore explained, it remains energized.

'I'heindeinng motor 99 and its controlled'index disc 96 continues to revolve and at the end of one revolution of disc 96 which, as hereinbefore '.20 described, indexes the spindle carrier from one lstation to the other, dog 301 again operates plunger 3|9 throughthe intermediary lever 323 (see Fig. This first closes switch 321 but as interlock 345| is open no circuit is completed .25 through solenoid s45. -It then closes switch 32s,

but as interlock 3|4-| is open no starting circuit is completed through solenoid 3||. It then opens switch 325. This breaks the holding circuit through solenoid 3|4, cutting oil ahead .current lfrom index motor 99, opening interlock- 3|4--2 which causes no change as switch 338 completes a holding circuit through solenoid 350, and clos- -ing interlock 3|4-3. Closing this latter inter-- lock energizes index motor reverse solenoid 40| -35 as the plugging switch 402 is closed, thus sending 323. The energizing'of -solenoid 3|| closes slide motor ahead switch plunger 320 (Fig. 16) starting the slide motor 205 ahead. It also closes interlock 3|1| and the motor itself, as it starts ahead, closesy plugging switch 4'05, completing a circuit through solenoid 406. Y Energizing this coil closes holding circuit interlock 406|r and also interlock 406-2, the closing of this latter inter- .'-5 lock causing no change as the normally closed interlock 3|1-2 has `previously been opened by the energizing of solenoid 3 |1. The energizing of solenoid 3|1 also closes its Iholding circuit interlock 3|I-3. s

so 'Ihe slide motor 2051s now revolving ,the slide Ircam drum |1| ahead and dog 299 leaves plunger 233 allowing spring 344 (see Figs. 14, 161 and 17) to operate it, rst closing switch 336 which com--y pletes a ,holding circuit through solenoid 3|'| 3 l'I-SD and interlock 3|1-3. 'Further action of plunger 233 opens .switch 330. This breaks the holding circuit through solenoidv 350, opening lits 'holding interlock 350| and opening' interlock 7".) 333-2, thus breaking the starting circuit through' solenoid 3|'|.l Further' movement of `plunger 233 opens switch 331, but as no current.

is iiowing through the switch no change takes place.

"i5 Motor23l continues to revolve advancing the slides on their fast motion until a dog 30| adjustably located on slide .drum (see Figs. 3, 14,

`16) through the medium of lever 303`opens switch 43||-.SD, breaking the holding circuitv through solenoid 3|'| and thus opening the ahead switch of the slide motor 205. YDie-energizing solenoid 3|'l opens holding circuit interlock 3|1-3 so that when the dpg leaves the switch 3 'l-SD, allowing it to close, the holding circuit through solenoid 3|1 will remain broken. De-energizing of solenoid 3|'l opens interlock 3|1-|, but as interlock 406| is closed the holding circuit continues to flow through solenoid 406. De-energizing solenoid 3|'| also closes interlock 3|1-2 and as interlock 406-2 is closed a circuit is completed through solenoid 32| which, through switch plunger 322, closes the switch and sends a reverse current into motor 205. This causes the motor-to stop and then start to reverse, but the instant that it starts to reverse plugging switch 405 opens, breaking the circuit through solenoid 406. This action opens interlock 406- 2 thus breaking 'the' current through solenoid 32| and opening the reverse switch of motor 205, the

effect being. to stop the slide motor practically instantaneously.

De-energizing of solenoid 406 also opens its holding circuit interlockA S-4|. This is necessary since the rotor of motor 205 is positively connected with shaft |93, which shaft is, as hereinbefore described, rotated from the spindle drive meanswhen the machine is on the feeding cycle. The rotor, therefore, of motor 205 is idly revolved by this shaft and plugging switch 405 will close, and unless interlock 40B-IA is open, a circuit will be formed through solenoid 406 which would close interlock 406-2 and supply reverse current to motor 205.

The drive to drum is now picked up by worm gear 200 vthrough its-roller ratchet clutch 403, as hereinbefore described, and drum |1| is revolved at a'slow speed for its cutting operation.

.At any desired point in the cycle. as for instance when the tools finish their work on the subject piece, an adjustable dog 300 is set on drum |l| are closed, va circuit is formed through solenoid 3|1, starting the slide motor 205 aheadyv closing the various holding circuit interlocks for solenoid 3l1, and resetting the various 'plugging circuit interlocks so that the plugging circuit will again function when motor 205 isagain stopped, in the same manner as hereinbefore described.

Motor 205 now drives Vfeed shaft |93 and its controlled slides at the fast speed for` idle movements.

While the feeding cycle has been going on the y operator has been chucking a piece of work in the spindle at the loading station and as soon as he finishes chucking hemay close reset switch 3| 0. Inf the operator closes the switch 3|0 the machinewill not stop after it has iinished 'its cycle of operations, ibut another cycle of operations, such as indexing the spindle carrier, ad-

vancingthe tools to the work, feeding the tools while cutting, and returning the same to their` rear` position, will 'take place. If he doe's 'not close reset switch 3|0 the machine will stop on completion of the cycle, except for the operation of the spindle motor |22, This feature acts.v as a safety in that it'precludes, for example, the indexing of the spindle carrier while the operator is chucking a piece of work, or the moving of the tools into cutting position while he is chucking f lock partiallylcompletes a circuit through solenoid I chine, with the assurancethat the machine will continue its cycle and notime will be lost.

The manner by which this is accomplished is as follows: Closing switch 3|0 completes the circuit through solenoid 345, the energizing of which closes its holding circuit linterlock 345- l and interlock345-2. The closing. of this latter inter- 3|4,'but as switch 331 is open except when l -plungerh298 is operated by dog 299, (which takes place only when the tool slide has reached its extreme rear position with respect to the chuck) the circuit is not completed. When the tool slide reaches its extreme rear position, dog'299 operates plunger 298, first closing switch 331, completing the circuit through solenoid 3|4, thus starting the indexing motor 99 in the manner.

hereinbefore described. The energizing of solenoid 3|4 also opens interlock 3|4-I breaking the starting circuit through solenoid 3|1 and thus preventing starting of the slide motor 205 while index is taking place. Energizing of solenoid 3|4 opens interlock 3|4-3 which prevents the index plugging circuit from operating as plugging switch 402 is closed by the starting ofthe index motor 99. Energizing of solenoid 3|4 also closes interlock 3|4-2 completing a circuit through solenoid 350, the energizing of the latter closing its holding interlock 350-.| and interlock 350-'-2, butas interlock 3|4-| is open no starting circuit through solenoid 3|1 is formed. Plunger 298 then opens switch 336, breaking the holding circuit through ,the slide motor ahead solenoid 3|1 and stopping the slide motor 205 through the plugging circuit as hereinbefore described. The cycle now repeats itself.

If the operator does not close reset switch 3|0 before the dog 299 has acted upon plunger 298,

the closing of switch 331 by plunger 298 will not start the index motor (as interlock 345-2 will be open) and the slide motor 205', and therefore the feed shaft |93 and its connected tool slides, will simply come to a stop upon the opening of switch 336 by plunger 298.

After the machine has thus stopped the oper-v ator may start the cycle at any time by closing reset switch 3|0 as hereinbefore described.

The operator may at anytime during the automatic cycle start the fast idle motion of the' slides by closing hand operated switch SI1-GH,

the closing of which forms a circuit through solenoid 350 and thus through its 'controlled interlock 350-2 forming a starting y,circuit through the slide motor operating solenoid-3H.

The operator may stop the slide motor atany time during the automatic cycle and thus change from fast idlemovement to slow feeding movement by opening hand operated switch 3|1-'SH, the opening of this'switch breaking the holding circuit through slide motor controlling solenoid 3|1.

Manual operation As hereinbefore described clutch 202 can be operated' by hand lever 210 to disengage shaft |93 from worm gear 200 and this movement of hand lever 2.10 also acts to throwl transfer switch 301a, `to which it is operatively connected, into the manual control position, This disconnects live wire 218 from automatic control wire 218a and connects it The automatic control switches are now dead and the index motor is controlled by manual push button 3|| (see Figs. 1, 16 and'l'?) and the slide motor 205 may be jogged forward by hand push button 3|2 and reverse by hand push button 3|3.

It is necessary that when index is started, either by hand or automatically, that it continue until its completion and that the index motor 99 be plugged to a stop at the nish of the indexing cycle. Therefore, the holding circuit for the index motor solenoids 3|4 and 40| and the circuit for the plugging switch 402 are taken from the line 218 between the source of electrical supply and transfer switch 301a so that they are operative whether the control is manual or automatic.

with manual control wire 21821.

With manual operation of the slide motor 205,

however, it is desirous that the motor run forward or reverse only so long as the operator keeps the switch 3|2 or 3|3 closed. Therefore, the holding circuit for slide motor operating solenoids 3| 1 and 32| and the circuit for the plugging switch 405 are taken from the automatic line ning solthat interlock 28|-2 is closed and if the turret slide is in its extremerear position so that dog 299 las moved switch plunger 298 to close switch 331. It is therefore apparent that index cannot take place unless the spindle motor is running and unless 'the tool slide is in a certain predetermined position, preferably at the limit of its stroke away from the chuck. Immediately that index starts; dog 301 allows switch 325 to close, forming a holding circuit through solenoid 3|4, andthe operator may then release Vpush button switch. Index motor 99 completes the index and is plugged at the endof the index in the same manner as hereinabove described under Automatic control.

If push button 3|| has returned to its normal position the operator may jog the slide motor 205 forward by operating hand push button 3|2.

-This first cuts the reverse push button 3|3 out of the circuit and then forms a circuit through slide ahead solenoid 3|1 if index has been completed so that switch 326 is held closed by'dog 301. It

is therefore, apparent that the slide motor canI direction'by push button 3|3, the operation of which first cuts out the forward switch 3|2 and then energizes the slide reverse solenoid 32| if the hereinbeforestated switch 326 is held closed by dog 301.

As the holding circuits for both the slide ahead solenoid 3|1 and the slide reverse solenoid 32| are connected with the automatic line 210a, which line is dead when switch 301a is in the manual control position, no holding circuits are formed through these solenoids and they are energized to operate the motor only so long as the operator keeps push button 3|2 or 3|3 depressed.

Having thus described the invention and one example of how it may-be constructed and operated, it is to be understood that we are not to be limited to the exact construction, combination and arrangement of parts -herein disclosed as the 

